Finding the Fourth Proportional to 9,315.90, 12,855.24 and 5,124.42

Step by Step Solution

1. Step 1: Write the proportion equation
   9,315.90 : 12,855.24 = 5,124.42 : x
2. Step 2: Convert to fraction form
   9,315.90/12,855.24 = 5,124.42/x
3. Step 3: Cross multiply
   9,315.90x = 12,855.24 × 5,124.42
4. Step 4: Simplify right side
   9,315.90x = 65,875,648.96
5. Step 5: Solve for x
   x = 65,875,648.96/9,315.90
6. Step 6: Final answer
   x = 7,071.31